Airplane



Aug. 7, 1945. M. JENSEN 2,381,596

AIRRLANE Filed Sept-2, 1942 S eet 1 Aug-. 7, 1945. M. JENSEN 2,381,596

AIRPLANE Filed Sept. 2, 1942 2 Sheets-Sheet 2 Patented Aug 7, 1945Martin j'ensen, New York, N. Y.,' assignor to Langley AviationCorporation, New York, N. Y.,

' a corporation of Delaware Application September 2, 1942, Serial No.457,0?7 1 This invention relates to airplanes and in par-- ticular toairplanes having propulsion systems of multi-motor, contra-turningpropeller type.

An object of the invention is to provide a compact, simple, andefficient systemincluding the 1 feature, preferably, that the drive ofall' of the engines goes to all of the propellers. 1 1 1 While theinvention is not necessarily limited as to the type of engineused, itsadvantagesmay be realized to the fullest, extent when doublebank pancaketype engineslmounted flatwise in wing cavities are employed. In. the,use of such engines the normal .Wing section-needanot be disturbed andsince @excrescences. for the housing of the engines arethus..avoided,,parasite resistance is accordingly lessened. Utilizingthe wingcontained pancake engines, the ,new system permits the weightof. the engines ity. Consequently, the invention vfinds particularapplicability in the case iplanes-of combat type where speed andmaneuverabilityare essential. Efficiency and maneuverability are furtherenhanced'by the contra=turning propellers. 1

' In the further description of theinvention, reference will be -made.totheaccompanying drawings, which show .thenew arrangement .inillustrative embodiment. In these drawings:

Figure l is a plan view of a singletseater mono: plane 1 of fighter typeembodying 1 the invention.

Figure 2 isa front elevation oftheairplane of Figure 1.

Figure 3 is anelevation of the airplane as seen from the left hand sidewith the left hand wing in section on the line 3-3 of Figure 1, and

Figure 4 is an enlarged plan view of a gear box whereby the engines areconnected to the propeller shafts, the top of the gear box beingremoved.

The illustrated airplane has a main plane including the right and lefthand wings I0 and II which extend from a fuselage l2. The fuselageincludes a forward extension or nose portion l3, a central portion 14 inwhich the cockpit is disposed, and a tail portion l which supports theusual empennage IS. The roof [1 of portion I5 is elevated above the roofof the forward portion and the latter is faired into the former by atransparent windshield 18 at the cockpit. The airplane is provided witha tricycle landing gear including the struts l9 and 20 beneath the wingsand the strut 2| beneath the forward portion 13. In flight the struts I9and 20 can be moved toward the fuselage and then swung outwardly andupwardly to bring the wheels 22 and 23 into to be: effectivelycentralized and disposed for high maneuverabilcavities on the undersidesof the wings as indicated' in Figure 1. The strut 2| isadaptedtoubeswung upwardly and rearwardly in. order'tto bring the wheel 24- into asuitable cavity at the underside of the fuselage. 1 1 1 Twodouble-bankpancake type engines 25 and 26 are arranged flatwise in thewings Illand II, respectively, immediately adjacent the fuselage withtheir crank or power shafts 21 and 128' in alignment and with theiroutput ends adjacent each other. Preferably, andv as hereshown, thecommon axis of the engines-is coincident with the lateral'axis 29 of:the aircraft soithat the engines are substantially balanced about thisaxis. The power shafts 21 and 28 extend into the fuselage andin-to agear box 30 .disposedsubstantially atthe center of gravity and havebevel gears 3l'and32 of like size fixed ontheir respective extremitieswithin the box. clutches 33 and 34 are interposed in shafts 21 and 28respectively. 1 1. 1 Journaled in the forward wall of. the gear box, isa, hollow propeller shaft 35 and within the .box 30 shaft'35 has fixedthereona bevelgear-3B which engagesboth the-gears 3 l and 32. Propellershaft 35 extends forwardly on the longitudinal axis of the airplane ashere shown, its forward' portion being supported in a bearing 31 and-itsextremity having fixed thereon a propeller 38. A hollow propeller shaft39 is disposedcoaxially with, here shown as concentrically within, shaft35 and projects beyondboth ends of the latter. The rear end of shaft 39is journaledin the rear wall of'box 30 and within the box has securedthereon a bevel gear 40 of the same size as gear 36 and engaging both ofgears 3| and 32. The forward portion of shaft 39 is rotatable in abearing within shaft 35 and within hearing 31, and the forward extremityof the shaft has fixed thereon a propeller 4 i.

The power shafts 21 and 28 are similarly rotating, and by this I meanthat both shafts rotate either clockwise or counterclockwise when viewedfrom their output ends. This is an important feature of the invention,since it follows that the engines can be interchangeable. As indicatedby arrows in Figure 4, the shafts 21 and 28 rotate counterclockwise andthrough the intermediary of the engaged bevel gears the propeller shafts35 and 39 will be driven counterclockwise and clockwise, respectively,as seen from the front, and at the same speed, driving the propellers38. and 4| in opposite directions.

If one engine should fail, it should be cut out, since otherwise itwould have to be driven by Overrunning v .the remaining engine. It isfor this reason that I provide means such as the overrunning clutches 33and 34 in advance of gears 3| and 32. Upon the failure of either engineit will be immediately disconnected from the drive gearing as the otherengine continues to drive both of the propellers.

The described arrangement permits the engines to be located close to thelongitudinal axis of the airplane, and while I have shown them just tothe sides of the fuslage, their adjacent ends might be in the latter tosome extent. In any event, the width of the fuselage need be onlysuflicient to accommodate the pilot, the narrow fuselage enabling theair resistance of this member to be kept at a minimum. By using thepancake type engines disposed entirely within normal wing sec tions, theparasite resistance of special nacelles, cowling, etc., is eliminated,and visibility isv enhanced. Access may be had to the engines throughremovable wing panels. With the Weights all centered about the center ofgravity, at which the engine axes intersect the axis of the propellershafts, a highly maneuverable plane is made possible.

Struts I9 and 20 of the landing gear, it will be observed, are under theouter portions of the engines so as to be able to take their weight inlanding.

In the case of a fighter plane, a cannon or gun 42 may be mounted withits breech portion in the cockpit immediately behind shaft 39 and withits barrel extending with clearance through the latter. The breechportion is readily accessible to the pilots seat 43, as indicated inFigures 1 and3.

The described arrangement of parts with reference to the center ofgravity is the most satisfactory but the invention is not necessarilylimited thereto. The engines should be substantially balanced onopposite sides of the vertical central longitudinal plane, but theiraxes can be outside the lateral axis of the airplane. The axis of thepropeller shafts may be non-coincident with the longitudinal axis of theairplane, although it should be substantially in the vertical centrallongitudinal plane of the craft. In the drawings the engines are shownas being entirely in the wings, but, as has been mentioned, theiradjacent ends may extend into the fuselage to further concentrate theirweights in the vicinity of the center of gravity. With the describednarrow fuselage, the engines will be at least partly in the wings and Iintend to include such disposition in speaking of engines mounted in thewings. Whilethe contemplated under the following claim, as will beunderstood. In stating that the output ends of the engine power shaftsare adjacent each other I do not refer to propinquity, but mean merelythat the engines are opposed with the output ends of their power shaftsdirected toward each other.

' In speaking ofthe axis of the propeller shafts as extendingtransversely of the power shaft axis, intersection is not necessarilyimplied. The term main plane, unless modified, is intended to coverwings with interposed fuselage, as shown, or a plane uninterrupted by afuselage. The term fuselage is used as including a body, such as anacelle, which does not run'to the tail surfaces.

I claim: i

In an airplane, a fuselage, a main plane comprising wings extending fromthe sides of the fuselage, a pair of similarly rotating pancake typeengines arranged flatwise in said wings respectively at opposite sidesof the central vertical 1ongitudinal plane of the airplane and havingsubstantially aligned power shafts with output ends extending into theinterior of the fuselage, a pair of-concentric propeller shafts arrangedsubstantially in the central vertical longitudinal plane of the airplanewith their input ends in said fuselage adjacent said output ends, theopposite ends of said propeller shafts projecting longitudinally of thefuselage for the mountingof propellers thereon, a gearing assembly inthe fuselage substantially at the center of gravity of the airplaneconnecting said output ends with said input ends whereby the propellershafts are driven in opposite directions; said gearing assemblyincluding bevel gears respectively driven from and in the same directionas 'said output ends, and bevel gears on said input ends respectivelyand both engaged by each of the first-mentioned gears; and overrunningclutches in the drives between said engines respectively and saidpropeller shafts.

14:1: 'a MARTIN JENSEN.

